#region License
// Copyright (c) .NET Foundation and contributors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// The latest version of this file can be found at https://github.com/FluentValidation/FluentValidation
#endregion

namespace FluentValidation.Validators;

using System;
using System.Linq;

public class StringEnumValidator<T> : PropertyValidator<T, string> {
	private readonly bool _caseSensitive;
	private readonly string[] _enumNames;

	public override string Name => "StringEnumValidator";

	public StringEnumValidator(Type enumType, bool caseSensitive) {
		if (enumType == null) throw new ArgumentNullException(nameof(enumType));

		CheckTypeIsEnum(enumType);

		_caseSensitive = caseSensitive;
		_enumNames = Enum.GetNames(enumType);
	}

	public override bool IsValid(ValidationContext<T> context, string value) {
		if (value == null) return true;
		var comparison = _caseSensitive ? StringComparison.Ordinal : StringComparison.OrdinalIgnoreCase;
		return _enumNames.Any(n => n.Equals(value, comparison));
	}

	private void CheckTypeIsEnum(Type enumType) {
		if (!enumType.IsEnum) {
			string message = $"The type '{enumType.Name}' is not an enum and can't be used with IsEnumName.";
			throw new ArgumentOutOfRangeException(nameof(enumType), message);
		}
	}

	protected override string GetDefaultMessageTemplate(string errorCode) {
		// Intentionally the same message as EnumValidator.
		return Localized(errorCode, "EnumValidator");
	}
}
